BACKGROUND: Short adults have an increased risk of type 2 diabetes. Although adult height results from childhood growth, the effects of height and growth trajectories during childhood are sparsely investigated. We investigated sex-specific associations between childhood height, growth and adult type 2 diabetes, including potential influences of birthweight and childhood body mass index (BMI).

METHODS: We followed 292 827 individuals, born 1930-83, from the Copenhagen School Health Records Register in national registers for type 2 diabetes (11 548 men; 7472 women). Weights and heights were measured at ages 7-13 years. Hazard ratios (HR) of type 2 diabetes (age ≥30 years) were estimated without and with adjustment for birthweight and BMI.

RESULTS: In men, associations between height and type 2 diabetes changed from inverse for below-average heights at age 7 years to positive for above-average heights at 13 years. No consistent associations were observed among women. These associations were not affected by birthweight. After adjustment for BMI, below-average childhood heights were inversely associated with type 2 diabetes among men (HR range: 0.91-0.93 per z-score) but above-average heights were not. Among women, after adjustment for BMI, below- and above-average heights in childhood were inversely associated with type 2 diabetes (HR range: 0.91-0.95). Greater height growth from 7 to 13 years was positively associated with type 2 diabetes in men and women.

CONCLUSIONS: After adjustment for BMI, short childhood height at all ages and greater growth during childhood are associated with an increased risk of type 2 diabetes, suggesting that this period of life warrants mechanistic investigations.